26th April 2020 at 8:35 pm #25541
Hi folks! Haven’t been online here for a while.
After almost exactly 1.5 years, I have finished my 1979 KZ750-B4 project! See below for before and after pics.
I would have been done last June or July, but just before I was done I had an accident at work and snapped the tendon in my right bicep in half. That forced me to stop and wait till now to finish it up.
When I bought this bike the original plan was to tune it up, put some new tires and chain on it, maybe hit it with some spray paint, then ride the F#*K out of it! However, as I dove into the bike I realized more and more that the previous owner should be banned for life from ever touching a bike again. The wiring harness was cut, then held together with loosely wrapped pieces of tape, and speaker wire in place of automotive wire. The carbs were supposed to have been “rebuilt”. Well, parts were missing, floats were at different heights. Rear suspension (Koni shocks) had no oil in them. I was told that the front forks were leaking. It made sense that they were because they were set at different heights in the triple trees. Also, the left fork bolt (where the springs and oil are inserted) was frozen in place. The list goes on, and on, and on…….and on some more. LOL! The one thing that was in good shape were the internals of the motor (thankfully , the previous owner was scared to open up the motor). Compression was good, valves were in good shape, cam chain was good.
So, I ended up taking it all apart, removing the motor from the frame, and then got to work. I had the frame, triple trees, battery and tool box, calipers footpeg brackets, and taillight mount I fabricated (probably more stuff that I’ve forgotten) sent out for powdercoat.
The front suspension was replaced with Progressive Suspension fork springs, fresh oil, and seals (I was able to remove the frozen left fork cap over two days of applying a generous amount of PB Blaster, heat, and a 3 foot long breaker bar. When it released it made a loud CRACK!!!! I was certain I had split the fork tube. Thankfully, I had not!). The rear Koni shocks were also rebuilt with a rebuild kit I got for $25 from Ikon Suspension (the U.S. based company that took over the motorcycle division of Koni), and fresh oil.
Front calipers were both rebuilt with fresh seals, and new pistons. Rear calipers got new seals. Also, I converted the front to dual brakes, and installed steel braided brake lines front and rear. The master cylinder is a modern reproduction of a Z1 master cylinder with a 5/8″ piston to accommodate the dual front brakes. This thing now stops on a dime.
I replaced the front fender with shorter one off of a KZ650. I liked the look better.
New stock gearing front and rear sprockets with a new, gold color chain were installed.
Carbs were completely gone through, float heights reset, all jets replaced with new (all stock size), and new gaskets and o-rings. The carb intake boots were split, so I sealed the splits with black RTV silicone sealant. I then got 3″ diameter heat shrink tubing, slid it over the boots, shrunk it, and installed the boots. They look brand new, and are now well supported so they won’t likely split again (or anytime soon, at least). I had to do the same to the crankcase breather tube. Sealed the cracks and splits with blac RTV, covered with heat shrink tubing, and installed.
Ignition and charging system was all replaced with new components from Rick’s Motorsport Electrics. New stator, new regulator/rectifier, new points and condenser. I also bought a spark booster from Dynatek Ignition Systems. It’s supposed to enhance the spark, give you more consistent and hotter spark. I have yet to install it as I want to ride the bike for a while as is, then install it and see if I feel any kind of difference.
The starter would make a horrible noise. I was lucky enough to find a brand new starter clutch on ebay and installed that. Now it starts up no problem with the button or with the kick.
The speedo and tach were shaking in their housings. Both were missing the screws that hold everything in place. I replaced the screws which snugged it all up, but I was certain that they would have been useless. I’m happy to say that they work perfectly! I’m so surprised! No shaking or bouncing needles. The bottoms were replaced with chrome covers. I painted the tops to clean them up.
Exhaust was replaced with a MAC 2 into 2 chrome headers and mufflers. I like them a lot! They sound good, work well, were easy enough to mount. That being said, I’d like to find a stock set of headers with the cross-over, paint them black, and install a pair of EMGO short, reverse cone mufflers that are black with a chrome tip. That will happen somewhere down the road.
Side covers were replaced with covers from a kz750T. I like them much better than the stock ones.
I wanted a shorter rear fender, but didn’t want to cut up the one I had (I kept all of the old parts I took off to have them for the future. I couldn’t bring myself to cut up anything on this bike, so I saved all the stock parts, then bought beat up old parts that I then cut up). Used an old, rusty one I bought at the salvage yard and cut it short. I did the same with a stock taillight mount and fabricated a new back plate for the LED brake light I used.
Speaking of lights, I got a new headlight and ring that has orange LED’s in the light. those are now my front turn signals. I’m not usually a big fan of LED’s but they worked out well in this application.
New seat from Texavina.com. Looks great, very well made with a steel seat pan that is powder coated black, has the rubber bumpers already installed, and all holes already threaded.
Front fairing is an ebay special from China. I loved the yellow windscreen and actually designed the entire look of the bike around that.
Pirelli Sport Demon tires.
I did a bunch of body work to the tail and tank. Had to plastic weld the tail in various spots, and pull out a big dent in the tank. Then bondo, and satin black spray paint and matte clear. After all that, I took all the bodywork, and the tank and side cover emblems to a painter. He applied the gold racing stripes and then shot it all with automotive matte clear.
On the left and right hand control clusters I hand painted the letters with gold paint to match the stripes.
That’s all I can write for now. I probably missed some stuff. If I remember anything I’ll add it later.
Anyway, I hope someone enjoys all that writing HAHAHA.
Really quick final note, with the COVID-19 pandemic going on, all the DMV’s are closed so I can not register or get a license plate for the bike right now. How frustrating!! Bike is done, weather is perfect, and I can’t legally ride it. Bummer! So, I just take it around the neighborhood for now. Hopefully I’ll be able to get a plate, soon.
Ok folks, take care!27th April 2020 at 1:06 pm #25544
That’s one hell of a write up and what an amazing transformation.
It is so frustrating as things are but hopefully we will be able to get out again soon.
KK27th April 2020 at 1:46 pm #25546
Good one Kon, you certainly put the work into that one!27th April 2020 at 5:29 pm #25547
Thanks! It definitely has been, all in all, a fun and satisfying process.
Yes, I’m frustrated by not being able to ride, but it should clear up soon enough.27th April 2020 at 5:31 pm #25548
Thanks coleighf! Yes, it was a lot of work! Now, though, it’s all mine! I know every inch of it.
It’s a lot more fun to ride than I though it would be. Mainly, I’ve ridden kz900’s for the last 30 years, so wasn’t sure how this would stack up. Honestly, I’m quite happy! It’s got enough power, is quick enough for me, and handles well.
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